Tetrathiafulvalenium salt

Having reviewed the latest developments in synthetic chemistry, several other aspects of the radical-polar crossover reaction have been investigated. One of these concerns attempts to effect S, 2 substitutions at the hitherto unreactive primary tetrathiafulvalenium salts. Three potential nucleophiles have been examined, and whereas each has afforded a facile reaction, none effected a simple S 2 displacement. First, attack by sodium azide on a series of primary tetrathiafulvalenium salts led to formation of TTF, but not by direct displacement. The route shown in Scheme 10 for (3c) could explain the observed products although the thioketene (59) was never isolated in these reactions. 

Only one example of A, iV-dialkyl diazonium salt was studied, but it provided key information on the mechanism of the solvolysis step in the radical-polar crossover scheme [10]. Thus, the A -allyl substrate 27 was reacted in moist acetone and afforded the primary alcohol 28. Since previous primary substrates, for example la, had afforded tetrathiafulvalenium salts 2a which did not undergo solvolysis, this showed that the A -allyl group was important in exerting a neighboring group effect, assisting the solvolysis of salt 29 via delocalized cation 30. Since ort/m-alkoxy... 

During the above synthesis, the diazonium salt 46 had led to 47 as the sole isolated product. The predicted intermediate tetrathiafulvalenium salt from this reaction, 50,... 

M. B. Inoue, M. Inoue, Q. Fernando, and K. W. Neb-esny. Highly electroconductive tetrathiafulvalenium salts of copper halides, Inorg. Chem. 25 3976 (1986). 

When the sodium salt of diethyl malonate was used as nucleophile on salt (60), again no direct substitution was observed, but the regio-chemistry of addition to the tetrathiafulvalenium nucleus was completely different. Here attack occurred on the internal carbon-carbon double bond via (61). This was followed by elimination to afford the isolated product (62), the structure of which was confirmed by X-ray analysis. ... 

The tetrakis(methylthio)tetrathiafulvalenium (CH3S)4TTF+ salt of [Mo6C18(NCS)6]2 was prepared in the same manner as... 

X 10 S cm ). On the basis of electronic spectra it was concluded that these CT complexes are to be regarded as tetrathiafulvalenium and not ferrocenium salts. Since no structural study was reported, how donor and acceptor molecules are arranged in the solid state and how to explain the observed conductivity, remains a matter of speculation. Furthermore, the two isomers were not separated, although it would have been of interest to examine the differences in solid state properties due to isomerism. 

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